In western civilization, the period ruled by mysticism is known as the 'Dark Ages' and the 'Middle Ages'. I will assume that you know the nature of that period and the state of human existence in those ages. The Renaissance broke the rules of the mystics. "Renaissance" means the "rebirth". Few people today will care to remind you that it was a rebirth of reason - of man's mind.
Ayn RandThousands of years ago the first man discovered how to make fire. He was probably burnt at the stake he'd taught his brothers to light, but he left them a gift they had not conceived and he lifted darkness from the face of the Earth.
Ayn RandDefinitions are the guardians of rationality, the first line of defense against the chaos of mental disintegration.
Ayn RandDo not let your fire go out ... Do not let the Hero in your soul perish ... Check your road and the nature of your battle. The world you desired can be won. It exists, it is real, it is possible, it is yours.
Ayn RandA rational process is a moral process. You may make an error at any step of it, with nothing to protect you but your own severity, or you may try to cheat, to fake the evidence and evade the effort of the quest - but if devotion to the truth is the hallmark of morality, then there is no greater, nobler, more heroic form of devotion than the act of a man who assumes the responsibility of thinking.
Ayn Rand